Cardiac topics Flashcards
What ECG leads are associated with RV MI?
Inferior leads
- STE in V1, ST depression in V2 and STE III > II are indicators.
- Diagnosis confirmed in right precordial ECG with STE > 1mm in V4R or >0.5 in V4R and V1
What is the usual perfusion of the RV?
RCA via RV marginal branches
Which parts of the RV does the LAD typically supply?
- RV apex
- Anterior IV septum
- Part of the RV anterior wall adjacent to the septum
- In 15-20% a dominant LAD will result in a larger proportion of the RV free wall being supplied by the left sided circulation
What are the principles of management in heart failure after RVMI?
- Revascularisation
- Optimise RV preload
- Decrease RV afterload
- Maintain perfusion pressure (MAP > 65)
- Control arrhythmias
- Mechanical circulatory support
How to optimise RV preload in patients with RF failure?
RV is sensitive to both volume depletion and overload.
1. Caution flui bolus and observe response - if CVP increases and BP doesn’t then stop volume resus.
2. If CVP raised and signs of congestion then cautious diuresis should be trialled
Avoid drugs that decrease preload - e.g. nitrates and opiates
How do you decrease RV afterload?
- Correct hypoxaemia, avoid high PEEP
- Consider iNO or prostacyclin
What are the causes of mitral stenosis?
- rheumatic fever
- congenital
- malignant carcinoid
- prosthetic valve
What are the symptoms of mitral stenosis?
- dyspnoea
- fatigue
- palpitaitons
- chest pain
- systemic emboli
- haemoptysis
- chronic-bronchitis like picture
- increased resp tract infections
What are the signs of mitral stenosis?
- malar flush (occurs due to reduced CO)
- low volume pulse
- AF
- tapping, non-displaced apex
- loud s1
- rumbling mid-diastolic murmur
- raised JVP
- peripheral oedema
What might tests show in mitral stenosis?
ECG - p-mitrale, AF, RVH, progressive RAD
CXR - enlarged LA (double shadow in right cardiac silhouette), pulm oedema, MV calcification
ECHO - diagnostic
What signifies significant mitral stenosis?
Valve area < 1cm2/kg
Pressure gradient > 5mmHg = mod stenosis
10mmHg = severe stenosis
What is the normal mitral valve area?
4-6cm2
Symptoms usually occur when <2cm2
What is the medical management of mitral stenosis?
- Rate control AF
- Diuretics to decrease preload and pulm venous congestion
+/- anticoagulate
What are the possible complications of mitral stenosis?
Pulmonary hypertension
Emboli
Pressure from large LA on local structures e.g. horase voics (RLN), dysphagia (oesophagus), bronchial obstruction
IE
What are the haemodynamic considerations for mitral stenosis under anaesthesia?
- MS is a fixed cardiac output state
- SR should be maintained
- Low normal heart rate (< 70) to allow sufficient diastolic time for ventricular filling
- Preload - aim normovolaemia
- Afterload - because CO is fixed any decrease in SVR can decrease coronary perfusion - maintaining afterload is crucial
- Optimise PVR
- Avoid nitrous as it can increase PVR in pts where its already elevated
- Contractility - LV usually ok, RV may need support if signs of failure
What causes mitral regurg?
Functional - LV dilatation
Annular calcification
RF
IE
MV prolapse
Ruptured chodae tendinae
Papillary muscle dysfunction
Cardiomyopathy
Congential
Appetite suppressant e.g. fenfluramine, phentemie
Can be acute or chronic
Primary or secondary
What are the symptoms of mitral regurg?
SOB
Fatigue
Palpitations
IE
What are the signs of mitral regurg?
AF
Displaced hyperdynamic apex
RV heave
Soft S1
Splt S2
Loud P2
PSM radiating to axilla
What might tests show in mitral regurg?
ECG - AF, p-mitrale, LVH
CXR - Enlarged LA and LV, MV calcification, pulm oedema
ECHO - LV function, aetiology, assess severity, size of regurg jet
What is the medical management of mitral regurg?
Rate control AF
Diuretics
LVF management
+/- anticoagulate
What is the haemodynamic management of mitral regurg under anaesthesia?
- High normal heart rate (80-100) decreases LV filling time and promotes forward flow
- Preload - err on side of well filled will promote forward flow
Afterload - regurg fraction increases as SVR does. Caution with vasoconstrictors
Contractility - inotropes may be needed if LVF
What is a normal EF in mitral regurg?
70%
<60% represents LV dysfunction
